Master key



Oct. 11,1927.

. 1,645,407 H. SOREF MASTER KEY Filed April 17 1922 JNVENTOR HTTORNYS Patented Oct. 11,1927. f I 1,645,407

UNITED STATES'PATENT OFFICE.

HARRY SOREF, F MILWAUKEE, WISCONSIN, ASSIGNOR TO MASTER LOOK COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

MASTER KEY.

Application filed April 17, 1922. Serial No. 554,159.

The invention relates to an improved conrendered ineffective, and necessitated the restruction of master key, whereby it is better sort to other devices to effect the opening of adapted to the more efficient performance of a closed lock. its functions. But with the use of my invention, the

The invention resides in a master key in former objections are caused to disappear,

which the-end of the solid shank of the key and a single key wit-h its much wider range 50 is flush with the tumbler catch. The new of movement is enabled to effect an operaconstruction endows the key with a greater tion which has heretofore been possible only amplitude of movement in feeling for the after protracted effort requiring the trial, in

tumblers, and thus its range of serviceabilmany instances, of numerous keys to achieve ity is increased over the older forms of masthe immediate results flowing from the use of 55 ter keys, in which the shank has uniformly my invention. been provided with a projection extending The drawing illustrates the preferred beyond on the face of the tumbler catch, specific and most usual form in which the such projection in its engagement with the invention is embodied, in that the free or parts of the lock casing acting to limit the outer edge of the tumbler catch 12 is promovement of the key, and preventing the vided with opposite, narrow projections 13 proper positioning of the tumblers. and 14, extending axially with respect to the But in my improvement, the objections of shank 10 of the key, and slightly forward the older constructions are overcome, and of the front face of the tumbler catch 12,

the new form of key is rendered available and also slightly rearward of the rear face 65 for effective operation under all conditions. of the said catch.

The novel features residing in the inven- Having thus described my invention, what tion will be pointed out in the appended I claim and desire to secure by LettersPatclaims. entof the United States, is:

The drawing which accompanys this speci- 1. A master key provided with a solid 7 fication, shows in perspective view a key shank and fixed tumbler catch, the whole of embodying my invention. which latter is adapted to be entered in the Referring to the drawing, it will be noted lock casing, and the end of the shank being that the forward end of the shank 10 of the flush with the front face of the tumbler key terminates at 11 in the plane of the front catch. I

face of the tumbler catch 12. The omission 2. A master key provided with a solid of theusual projection extending forwardly shank and a fixed tumbler catch, the whole of the shank and beyond the front face of of which latter is adapted to be entered in the tumbler catch 12, removes an obstructhe lock casing, and the end of the shank tion which, in the older form of keys, acted being flush with the front face of the tum- 30 as an interference in many cases with the bler catch, the free edge of the tumbler catch successful operation of the key in opening being provided with opposite, narrow prothe lock when the key thereto had become jections extending axially with respect to the lost. The said projection pivoted in the far said shank.

side of the lock and often constituted an in- In testimony whereof, I have signed my terference by reason of its engagement with name at Milwaukee, this 15th day of April, the lock casing. It restricted the amplitude 1922.

of movement of the key so that the latter was HARRY SOREF. 

